The physical accuracy of the ISETCam camera simulation has been evaluated in prior publications. Several independent studies report a close correspondence between measured and simulated sensor performance [1]}, [2]}, [3]}. Additional validation is based on the use of physical principles: the optics is modeled in PBRT using physical principles of ray tracing and Snell’s Law [4]} and diffraction [5]}. To confirm the implementation we compared the optics simulations with these physical principles and the widely used commercial program, Zemax [6]}. The surface rendering (PBRT) is based on ray tracing algorithms, with an accurate simulation of physics of light and its interaction with many types of surfaces including metals, diffuse reflectors, retro-reflective materials, and glass. The interaction function is known as bidirectional reflectance distribution function (BRDF), is derived based on the real-world experiments, and the function itself is validated by comparing the measured results [7]}, [8]}. The three-dimensional models of the cars are derived from a 3D scan of a real car and the physical dimensions are accurate. The ambient light spectral characteristics were measured using a multispectral lighting capture system and are validated [9]}.
